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  Subjects -> VETERINARY SCIENCE (Total: 213 journals)
Showing 1 - 63 of 63 Journals sorted alphabetically
Acta Scientiae Veterinariae     Open Access   (Followers: 1)
Acta Veterinaria     Open Access   (Followers: 1)
Acta Veterinaria Brasilica     Open Access  
Acta Veterinaria Hungarica     Full-text available via subscription   (Followers: 2)
Acta Veterinaria Scandinavica     Open Access   (Followers: 1)
Advances in Animal Biosciences     Full-text available via subscription   (Followers: 9)
Advances in Small Animal Medicine and Surgery     Hybrid Journal  
Advances in Veterinary Medicine     Full-text available via subscription   (Followers: 12)
Advances in Veterinary Science and Comparative Medicine     Full-text available via subscription   (Followers: 12)
African Journal of Wildlife Research     Full-text available via subscription   (Followers: 1)
Alexandria Journal of Veterinary Sciences     Open Access  
American Journal of Animal and Veterinary Sciences     Open Access   (Followers: 8)
American Journal of Primatology     Hybrid Journal   (Followers: 11)
American Journal of Veterinary Research     Full-text available via subscription   (Followers: 21)
Anatomia, Histologia, Embryologia: Journal of Veterinary Medicine Series C     Hybrid Journal   (Followers: 3)
Animal Behaviour     Hybrid Journal   (Followers: 100)
Animal Feed Science and Technology     Hybrid Journal   (Followers: 5)
Animal Health Research Reviews     Hybrid Journal   (Followers: 3)
Animal Nutrition     Open Access   (Followers: 7)
Animal Reproduction     Open Access   (Followers: 1)
Animal Reproduction Science     Hybrid Journal   (Followers: 4)
Animals     Open Access   (Followers: 6)
Annals of Agricultural and Environmental Medicine     Open Access   (Followers: 1)
Annual Review of Animal Biosciences     Full-text available via subscription   (Followers: 4)
Anthrozoos : A Multidisciplinary Journal of The Interactions of People & Animals     Hybrid Journal   (Followers: 6)
Archives of Animal Nutrition     Hybrid Journal   (Followers: 6)
Archivos de Medicina Veterinaria     Open Access   (Followers: 1)
Arquivo Brasileiro de Medicina Veterinária e Zootecnia     Open Access  
Arquivos de Ciências Veterinárias e Zoologia da UNIPAR     Open Access  
Ars Veterinaria     Open Access  
Asian Journal of Medical and Biological Research     Open Access   (Followers: 1)
Asian Journal of Poultry Science     Open Access   (Followers: 4)
Atatürk Üniversitesi Veteriner Bilimleri Dergisi     Open Access  
Australian Equine Veterinarian     Full-text available via subscription   (Followers: 3)
Australian Veterinary Journal     Hybrid Journal   (Followers: 15)
Avances en Ciencias Veterinarias     Open Access  
Avian Diseases     Full-text available via subscription   (Followers: 3)
Avian Pathology     Hybrid Journal   (Followers: 2)
Bangladesh Journal of Animal Science     Open Access  
Bangladesh Journal of Veterinary Medicine     Open Access   (Followers: 1)
Bangladesh Veterinarian     Open Access  
BMC Veterinary Research     Open Access   (Followers: 10)
Brazilian Journal of Veterinary Research and Animal Science     Open Access   (Followers: 8)
Buletin Peternakan : Bulletin of Animal Science     Full-text available via subscription  
Buletin Veteriner Udayana     Open Access  
Bulletin of Animal Health and Production in Africa     Full-text available via subscription   (Followers: 1)
Bulletin of the Veterinary Institute in Pulawy     Open Access  
Bulletin of University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca : Food Science and Technology     Open Access  
Canadian Journal of Veterinary Research     Full-text available via subscription   (Followers: 8)
Case Reports in Veterinary Medicine     Open Access   (Followers: 5)
Ciência Animal Brasileira     Open Access  
Ciência Rural     Open Access  
Cogent Food & Agriculture     Open Access  
Companion Animal     Full-text available via subscription   (Followers: 8)
Domestic Animal Endocrinology     Hybrid Journal   (Followers: 4)
Equine Health     Full-text available via subscription   (Followers: 3)
Equine Veterinary Education     Hybrid Journal   (Followers: 9)
Equine Veterinary Journal     Hybrid Journal   (Followers: 13)
Ethiopian Veterinary Journal     Open Access   (Followers: 5)
Eurasian Journal of Veterinary Sciences     Open Access   (Followers: 1)
FAVE Sección Ciencias Veterinarias     Open Access  
Frontiers in Veterinary Science     Open Access   (Followers: 1)
Global Journal of Animal Scientific Research     Open Access   (Followers: 1)
Human & Veterinary Medicine - International Journal of the Bioflux Society     Open Access   (Followers: 5)
ILAR Journal     Hybrid Journal  
In Practice     Full-text available via subscription   (Followers: 2)
Indian Journal of Animal Sciences     Open Access   (Followers: 4)
Indian Journal of Veterinary Anatomy     Full-text available via subscription   (Followers: 4)
Indonesia Medicus Veterinus     Open Access  
Intas Polivet     Full-text available via subscription  
International Journal for Agro Veterinary and Medical Sciences     Open Access   (Followers: 2)
International Journal of Livestock Research     Open Access  
International Journal of Veterinary Science and Medicine     Open Access   (Followers: 4)
Iranian Journal of Applied Animal Science     Open Access  
Irish Veterinary Journal     Open Access   (Followers: 5)
İstanbul Üniversitesi Veteriner Fakültesi Dergisi     Open Access  
Journal of Veterinary Science & Technology     Open Access   (Followers: 6)
Journal of Advanced Veterinary and Animal Research     Open Access   (Followers: 5)
Journal of Animal Behaviour and Biometeorology     Open Access   (Followers: 1)
Journal of Animal Physiology and Animal Nutrition     Hybrid Journal   (Followers: 5)
Journal of Animal Science and Technology     Open Access  
Journal of Applied Animal Nutrition     Hybrid Journal   (Followers: 3)
Journal of Avian Medicine and Surgery     Full-text available via subscription   (Followers: 5)
Journal of Buffalo Science     Hybrid Journal  
Journal of Equine Veterinary Science     Hybrid Journal   (Followers: 11)
Journal of Exotic Pet Medicine     Full-text available via subscription   (Followers: 3)
Journal of Experimental and Applied Animal Sciences     Open Access   (Followers: 1)
Journal of Feline Medicine & Surgery     Hybrid Journal   (Followers: 4)
Journal of Research in Forestry, Wildlife and Environment     Open Access   (Followers: 3)
Journal of Small Animal Practice     Hybrid Journal   (Followers: 11)
Journal of the American Veterinary Medical Association     Full-text available via subscription   (Followers: 27)
Journal of the Selva Andina Research Society     Open Access  
Journal of the South African Veterinary Association     Open Access   (Followers: 2)
Journal of Venomous Animals and Toxins     Open Access   (Followers: 4)
Journal of Veterinary Advances     Open Access   (Followers: 4)
Journal of Veterinary Behavior: Clinical Applications and Research     Hybrid Journal   (Followers: 4)
Journal of Veterinary Cardiology     Full-text available via subscription   (Followers: 7)
Journal of Veterinary Diagnostic Investigation     Hybrid Journal   (Followers: 8)
Journal of Veterinary Emergency and Critical Care     Hybrid Journal   (Followers: 15)
Journal of Veterinary Internal Medicine     Open Access   (Followers: 19)
Journal of Veterinary Medical Education     Partially Free   (Followers: 11)
Journal of Veterinary Medicine     Open Access   (Followers: 8)
Journal of Veterinary Medicine and Animal Health     Open Access   (Followers: 4)
Journal of Veterinary Pharmacology and Therapeutics     Hybrid Journal   (Followers: 8)
Journal of Veterinary Research     Open Access  
Journal of Veterinary Science & Medical Diagnosis     Hybrid Journal   (Followers: 4)
Journal of Zoo and Aquarium Research     Open Access   (Followers: 2)
Journal of Zoo and Wildlife Medicine     Full-text available via subscription   (Followers: 5)
Jurnal Agripet     Open Access  
Kenya Veterinarian     Full-text available via subscription   (Followers: 2)
kleintier konkret     Hybrid Journal  
Livestock     Full-text available via subscription   (Followers: 1)
Macedonian Veterinary Review     Open Access   (Followers: 2)
MEDIA PETERNAKAN - Journal of Animal Science and Technology     Open Access   (Followers: 1)
Medical Mycology     Open Access   (Followers: 3)
Medical Mycology Case Reports     Open Access  
Microbes and Health     Open Access   (Followers: 1)
New Zealand Veterinary Journal     Full-text available via subscription   (Followers: 11)
New Zealand Veterinary Nurse     Full-text available via subscription   (Followers: 3)
Nigerian Veterinary Journal     Open Access  
Nutrición Animal Tropical     Open Access   (Followers: 1)
Onderstepoort Journal of Veterinary Research     Open Access   (Followers: 3)
Open Access Animal Physiology     Open Access   (Followers: 4)
Open Journal of Animal Sciences     Open Access   (Followers: 4)
Open Journal of Veterinary Medicine     Open Access   (Followers: 4)
Pesquisa Veterinária Brasileira     Open Access  
pferde spiegel     Hybrid Journal  
Polish Journal of Veterinary Sciences     Open Access   (Followers: 3)
Pratique Médicale et Chirurgicale de l'Animal de Compagnie     Full-text available via subscription  
Preventive Veterinary Medicine     Hybrid Journal   (Followers: 10)
REDVET. Revista Electrónica de Veterinaria     Open Access  
Reproduction in Domestic Animals     Hybrid Journal   (Followers: 1)
Research & Reviews : Journal of Veterinary Science and Technology     Full-text available via subscription   (Followers: 1)
Research in Veterinary Science     Hybrid Journal   (Followers: 10)
Research Journal of Veterinary Sciences     Open Access   (Followers: 8)
Revista Brasileira de Ciência Veterinária     Open Access  
Revista Brasileira de Higiene e Sanidade Animal     Open Access  
Revista Brasileira de Parasitologia Veterinaria     Open Access  
Revista Brasileira de Reprodução Animal     Open Access  
Revista Brasileira de Zootecnia     Open Access   (Followers: 2)
Revista Ciencia Animal     Open Access  
Revista Ciencias Veterinarias     Open Access  
Revista Científica     Open Access  
Revista Colombiana de Ciencias Pecuarias (Colombian journal of animal science and veterinary medicine)     Open Access   (Followers: 1)
Revista Complutense de Ciencias Veterinarias     Open Access  
Revista da Sociedade Brasileira de Ciência em Animais de Laboratório     Open Access  
Revista de Ciências Agroveterinárias     Open Access  
Revista de Educação Continuada em Medicina Veterinária e Zootecnia     Open Access  
Revista de Investigaciones Veterinarias del Perú     Open Access  
Revista de la Facultad de Medicina Veterinaria y de Zootecnia     Open Access   (Followers: 1)
Revista de Medicina Veterinaria     Open Access  
Revista de Salud Animal     Open Access  
Revista Mexicana de Ciencias Pecuarias     Open Access  
Revista MVZ Córdoba     Open Access  
Revista Veterinaria     Open Access  
Revue Marocaine des Sciences Agronomiques et Vétérinaires     Open Access  
SA Stud Breeder / SA Stoetteler     Full-text available via subscription  
Schweizer Archiv für Tierheilkunde     Hybrid Journal  
Scientific Journal of Animal Science     Open Access   (Followers: 3)
Scientific Journal of Veterinary Advances     Open Access   (Followers: 1)
Small Ruminant Research     Hybrid Journal   (Followers: 2)
Sokoto Journal of Veterinary Sciences     Open Access   (Followers: 1)
Spei Domus     Open Access  
Tanzania Veterinary Journal     Full-text available via subscription   (Followers: 1)
team.konkret     Open Access  
The Dairy Mail     Full-text available via subscription   (Followers: 3)
Theriogenology     Hybrid Journal   (Followers: 1)
Topics in Companion Animal Medicine     Hybrid Journal   (Followers: 3)
Transboundary and Emerging Diseases     Hybrid Journal   (Followers: 2)
Trends in Animal and Veterinary Sciences     Open Access   (Followers: 5)
Trends in Parasitology     Full-text available via subscription   (Followers: 9)
Tropical Animal Health and Production     Hybrid Journal  
Tropical Veterinarian     Full-text available via subscription   (Followers: 1)
Turkish Journal of Veterinary and Animal Sciences     Open Access  
veterinär spiegel     Hybrid Journal   (Followers: 1)
Veterinária e Zootecnia     Open Access  
Veterinária em Foco     Open Access  
Veterinaria México     Open Access  
Veterinária Notícias     Open Access  
Veterinary Anaesthesia and Analgesia     Hybrid Journal   (Followers: 11)
Veterinary and Comparative Oncology     Hybrid Journal   (Followers: 7)
Veterinary Clinical Pathology     Hybrid Journal   (Followers: 9)
Veterinary Clinics of North America: Equine Practice     Full-text available via subscription   (Followers: 9)
Veterinary Clinics of North America: Exotic Animal Practice     Full-text available via subscription   (Followers: 7)
Veterinary Clinics of North America: Food Animal Practice     Full-text available via subscription   (Followers: 5)
Veterinary Clinics of North America: Small Animal Practice     Full-text available via subscription   (Followers: 15)
Veterinary Dermatology     Hybrid Journal   (Followers: 7)
Veterinary Immunology and Immunopathology     Hybrid Journal   (Followers: 10)
Veterinary Journal     Hybrid Journal   (Followers: 15)
Veterinary Medicine and Animal Sciences     Open Access   (Followers: 3)
Veterinary Medicine and Science     Open Access  
Veterinary Medicine International     Open Access   (Followers: 7)
Veterinary Medicine: Research and Reports     Open Access   (Followers: 4)
Veterinary Microbiology     Hybrid Journal   (Followers: 8)
Veterinary Nurse     Full-text available via subscription   (Followers: 3)
Veterinary Nursing Journal     Hybrid Journal   (Followers: 3)
Veterinary Ophthalmology     Hybrid Journal   (Followers: 6)
Veterinary Parasitology     Hybrid Journal   (Followers: 9)
Veterinary Pathology     Full-text available via subscription   (Followers: 14)
Veterinary Quarterly     Hybrid Journal   (Followers: 3)

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Journal Cover Veterinary Microbiology
  [SJR: 1.425]   [H-I: 84]   [8 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 0378-1135 - ISSN (Online) 1873-2542
   Published by Elsevier Homepage  [2970 journals]
  • Therapeutic effect of Pseudomonas aeruginosa phage YH30 on mink
           hemorrhagic pneumonia
    • Abstract: Publication date: 15 July 2016
      Source:Veterinary Microbiology, Volume 190
      Author(s): Jingmin Gu, Xinwei Li, Mei Yang, Chongtao Du, Ziyin Cui, Pengjuan Gong, Feifei Xia, Jun Song, Lei Zhang, Juecheng Li, Chuang Yu, Changjiang Sun, Xin Feng, Liancheng Lei, Wenyu Han
      Hemorrhagic pneumonia caused by Pseudomonas aeruginosa remains one of the most costly infectious diseases among farmed mink and commonly leads to large economic losses during mink production. The objective of this study was to investigate the potential of using phages as a therapy against hemorrhagic pneumonia in mink. A broad-host-range phage from the Podoviridae family, YH30, was isolated using the mink-originating P. aeruginosa (serotype G) D7 strain as a host. The genome of YH30 was 72,192bp (54.92% G+C), contained 86 open reading frames and lacked regions encoding known virulence factors, integration-related proteins or antibiotic resistance determinants. These characteristics make YH30 eligible for use in phage therapy. The results of a curative treatment experiment demonstrated that a single intranasal administration of YH30 was sufficient to cure hemorrhagic pneumonia in mink. The mean colony count of P. aeruginosa in the blood and lung of YH30-protected mink was less than 103 CFU/mL (g) within 24h of bacterial challenge and ultimately became undetectable, whereas that in unprotected mink reached more than 108 CFU/mL (g). Additionally, YH30 dramatically improved the pathological manifestations of lung injury in mink with hemorrhagic pneumonia. Our work demonstrates the potential of phages to treat P. aeruginosa-caused hemorrhagic pneumonia in mink.


      PubDate: 2016-05-26T14:45:33Z
       
  • Outbreak of mortality in Russian (Acipenser gueldenstaedtii) and Siberian
           (Acipenser baerii) sturgeons associated with sturgeon nucleo-cytoplasmatic
           large DNA virus
    • Abstract: Publication date: Available online 25 May 2016
      Source:Veterinary Microbiology
      Author(s): S. Ciulli, E. Volpe, R. Sirri, P.L. Passalacqua, F. Cesa Bianchi, P. Serratore, L. Mandrioli
      Diseased outbreaks with high mortality in farmed sturgeon are a limiting factor to the success of this emerging aquaculture sector in Europe. Thorough investigations of outbreaks can determine the aetiological agents, identify important pathological and epidemiological pathways of infections and pave the way for effective control strategies. A thorough investigation of a mortality outbreak in Russian (Acipenser gueldenstaedtii) and Siberian (Acipenser baerii) sturgeons in Italy, demonstrated the primary involvement of a sturgeon nucleo-cytoplasmic large DNA virus (NCLDV). While, the taxonomy classification of this new virus is still uncertain, its involvement in sturgeon mortality outbreaks in Europe is, for the first time, fully investigated and described. Furthermore, the coinfection of bacteria such as motile Aeromonas spp. and Acinetobacter spp. was reported. Genetic characterisation showed the close relationship between the European sturgeon NCLDV with North American NCLDVs. Similarly to the latter, the European sturgeon NCLDV persists in survivors. Furthermore, a systemic distribution of the European sturgeon NCLDV was evident in diseased A. baerii and A. gueldenstaedtii and in recovered A. gueldenstaedtii. These epidemiological and pathological findings will help in the identification of effective control strategies for sturgeon NCLDV infection, which afflict an important and emerging European aquaculture sector.


      PubDate: 2016-05-26T14:45:33Z
       
  • Mycoplasma hyopneumoniae and Mycoplasma flocculare differential domains
           from orthologous surface proteins induce distinct cellular immune
           responses in mice
    • Abstract: Publication date: Available online 17 May 2016
      Source:Veterinary Microbiology
      Author(s): Fernanda Munhoz dos Anjos Leal, Veridiana Gomes Virginio, Carolina Lumertz Martello, Jéssica Andrade Paes, Thiago J. Borges, Natália Jaeger, Cristina Bonorino, Henrique Bunselmeyer Ferreira
      Mycoplasma hyopneumoniae and Mycoplasma flocculare are two genetically close species found in the swine respiratory tract. Despite their similarities, while M. hyopneumoniae is the causative agent of porcine enzootic pneumonia, M. flocculare is a commensal bacterium. Genomic and transcriptional comparative analyses so far failed to explain the difference in pathogenicity between these two species. We then hypothesized that such difference might be, at least in part, explained by amino acid sequence and immunological or functional differences between ortholog surface proteins. In line with that, it was verified that approximately 85% of the ortholog surface proteins from M. hyopneumoniae 7448 and M. flocculare present one or more differential domains. To experimentally assess possible immunological implications of this kind of difference, the extracellular differential domains from one pair of orthologous surface proteins (MHP7448_0612, from M. hyopneumoniae, and MF_00357, from M. flocculare) were expressed in E. coli and used to immunize mice. The recombinant polypeptides (rMHP61267–169 and rMF35767–196, respectively) induced distinct cellular immune responses. While, rMHP61267–169 induced both Th1 and Th2 responses, rMF35767-196 induced just an early pro-inflammatory response. These results indicate that immunological properties determined by differential domains in orthologous surface protein might play a role in pathogenicity, contributing to elicit specific and differential immune responses against each species.
      Graphical abstract image

      PubDate: 2016-05-20T14:27:12Z
       
  • In vitro and in vivo studies on the antimicrobial effect of lactoferrin
           against Escherichia coli O157:H7
    • Abstract: Publication date: Available online 19 May 2016
      Source:Veterinary Microbiology
      Author(s): J. Rybarczyk, E. Kieckens, D. Vanrompay, E. Cox
      Escherichia coli O157:H7 shed by clinically healthy ruminants has been linked to hemorrhagic colitis and the hemolytic uremic syndrome in humans. The bacteria are spread mainly by contaminated food and water, contact with animals carrying the organisms, and person-to-person contact. Although many intervention strategies have been studied to reduce E. coli O157:H7 carriage in ruminants and its spread into the environment, none of the available methods can completely eliminate the infection. Therefore, there is need for new intervention strategies which will effectively reduce E. coli O157:H7 prevalence. Lactoferrin, a member of the transferrin protein family, is an iron-binding glycoprotein that is found in many exocrine secretions, including milk, tears, saliva, and serum. Lactoferrin has a number of biological functions including antimicrobial and immunomodulatory effects. This review summarizes latest data on the antimicrobial effect of lactoferrin against E. coli O157:H7 in in vitro and in vivo studies.


      PubDate: 2016-05-20T14:27:12Z
       
  • Bartonella melophagi in blood of domestic sheep (Ovis aries) and sheep
           keds (Melophagus ovinus) from the southwestern US: Cultures, genetic
           characterization, and ecological connections
    • Abstract: Publication date: Available online 18 May 2016
      Source:Veterinary Microbiology
      Author(s): Michael Kosoy, Ying Bai, Russell Enscore, Maria Rosales Rizzo, Scott Bender, Vsevolod Popov, Levent Albayrak, Yuriy Fofanov, Bruno Chomel
      Bartonella melophagi sp. nov. was isolated from domestic sheep blood and from sheep keds (Melophagus ovinus) from the southwestern United States. The sequence analyses of the reference strain performed by six molecular markers consistently demonstrated that B. melophagi relates to but differ from other Bartonella species isolated from domestic and wild ruminants. Presence of 183 genes specific for B. melophagi, being absent in genomes of other Bartonella species associated with ruminants also supports the separation of this bacterial species from species of other ruminants. Bartonella DNA was detected in all investigated sheep keds; however, culturing of these bacteria from sheep blood rejects a speculation that B. melophagi is an obligatory endosymbiont. Instead, the results support the hypothesis that the domestic sheep is a natural host reservoir for B. melophagi and the sheep ked its main vector. This bacterium was not isolated from the blood of bighorn sheep and domestic goats belonging to the same subfamily Caprinae. B. melophagi has also been shown to be zoonotic and needs to be investigated further.


      PubDate: 2016-05-20T14:27:12Z
       
  • Diversity of class 1 and 2 integrons detected in Escherichia coli isolates
           from diseased and apparently healthy dogs
    • Abstract: Publication date: Available online 13 May 2016
      Source:Veterinary Microbiology
      Author(s): Amanda K. Siqueira, Geovana B. Michael, Daniela F. Domingos, Mirtis M.G. Ferraz, Márcio G. Ribeiro, Stefan Schwarz, Domingos S. Leite
      Escherichia coli is one of the major pathogens causing urinary tract infections (UTIs) and pyometra in dogs. The aims of this study were to investigate canine E. coli isolates for the presence of class 1 and 2 integrons by PCR/sequencing and to characterize these isolates and their integron-carrying plasmids. Isolates were characterized by phylotyping, XbaI-macrorestriction analysis and plasmid transfer experiments. Plasmids were analyzed by S1 nuclease-PFGE, replicon typing, conjugation and restriction analysis. Antimicrobial resistance was investigated by antimicrobial susceptibility testing and PCR/sequencing. From 158 E. coli of dogs suffering from UTIs (n=51) and pyometra (n=52) or being apparently healthy (n=55), 13 isolates harboured class 1 (n=10) or class 2 integrons (n=3). They were distributed among the phylogenetic groups A (3/13), B1 (6/13), B2 (3/13) and D (1/13). Two isolates showed indistinguishable XbaI-patterns, but differed in the remaining characteristics. Another two isolates (UTI or apparently healthy) displayed different XbaI-patterns, but harboured similar plasmids. Integrons were found on plasmids of incompatibility groups IncF, IncF-IncFIC, IncFIB-IncHI2, IncFIB-IncN, IncFIC or IncHI2 and three of them were conjugative. Resistances to aminoglycosides, sulphonamides and trimethoprim were commonly detected. Class 1 integrons carried the gene cassette arrays dfrA12-orfF-aadA28, ΔdfrA17-aadA5, dfrA29, aadA7, aadA29 or dfrA12-orfF-aadA2-cmlA-aadA1. Class 2 integrons carried the array dfrA1-sat2-aadA30. Two extended-spectrum β-lactamase genes (bla CTX-M-2) and one AmpC β-lactamase gene (bla CMY-2) were also detected on plasmids. These findings indicate the potential risk of the dissemination and persistence of E. coli and/or integron-carrying plasmids in companion animals.


      PubDate: 2016-05-16T14:19:26Z
       
  • Piglets with maternally derived antibodies born from sows immunized with
           rAdV-SFV-E2 were completely protected against lethal CSFV challenge
    • Abstract: Publication date: Available online 14 May 2016
      Source:Veterinary Microbiology
      Author(s): Shui-Li Xia, Mingliang Du, Jian-Lin Lei, Yan Liu, Yimin Wang, Shengwei Ji, Guang-Tao Xiang, Lian-Feng Li, Xin Cong, Yuzi Luo, Lina Shao, Hua-Ji Qiu, Yuan Sun
      Classical swine fever (CSF) is an economically important infectious disease of pigs caused by Classical swine fever virus (CSFV). To facilitate the eradication of CSF in endemic areas, a marker vaccine enabling differentiation of infected from vaccinated animals (DIVA) is urgently needed. Previously, we have demonstrated that the DIVA vaccine rAdV-SFV-E2, an adenovirus-vectored Semliki Forest virus replicon expressing the E2 glycoprotein of CSFV, induces complete protection from lethal CSFV challenge. The aim of this study was to investigate whether maternally derived antibodies (MDAs) from sows immunized with rAdV-SFV-E2 can effectively protect piglets against lethal CSFV challenge. Three groups of five-week-old piglets (n=4), with or without MDAs, were challenged with the highly virulent CSFV Shimen strain. Clinical signs, CSFV-specific antibodies, viremia and pathological and histopathological changes were monitored. The results showed that the piglets with MDAs from the sow immunized with rAdV-SFV-E2 were protected clinically, virologically and pathologically, while the piglets with undetectable MDAs from the rAdV-SFV-E2-immunized sow were partially protected (2/4 survival), in contrast with the piglets from the non-vaccinated sow, which displayed CSF-typical clinical signs, viremia, deaths (4/4) and pathological/histopathological lesions. These results indicate that MDAs from the sow immunized with rAdV-SFV-E2 are able to confer full passive immunity to newborn piglets.


      PubDate: 2016-05-16T14:19:26Z
       
  • The pathogenicity and host adaptation of livestock-associated MRSA CC398
    • Abstract: Publication date: Available online 14 May 2016
      Source:Veterinary Microbiology
      Author(s): Britta Ballhausen, André Kriegeskorte, Sarah van Alen, Philipp Jung, Robin Köck, Georg Peters, Markus Bischoff, Karsten Becker
      The presence of methicillin-resistant S. aureus (MRSA) CC398 in livestock and their transmission to humans followed by their introduction into hospitals led to a significant burden for the human healthcare system, especially in regions with a high density of livestock breeding. The CC398 lineage made two host changes in its evolutionary history: From humans to pigs and other livestock-associated animals and back to the human host. These adaptation processes are mirrored by changes of the equipment with virulence factors necessary for successful host change. Here, we consider these factors and their special role during human colonization and infection. Host adaptation of S. aureus CC398 is accompanied by genetic changes that are mainly driven by exchanges of mobile genetic elements. So far, it is not clear, which virulence or adhesion factors are important for S. aureus CC398 in host interaction. Among human and animal-derived MRSA CC398 virulence factors, e.g. (entero-) toxins, were rarely found. Overall, this review provides a comprehensive overview on the emerging S. aureus lineage CC398 by summarizing current knowledge from microbiological, molecular and cellular interaction studies in relation to clinical and epidemiological perspectives.


      PubDate: 2016-05-16T14:19:26Z
       
  • Edwardsiella tarda EsaE (Orf19 protein) is required for the secretion of
           type III substrates, and pathogenesis in fish
    • Abstract: Publication date: Available online 9 May 2016
      Source:Veterinary Microbiology
      Author(s): Ying Zhou, Lu Yi Liu, Tian Tian He, Zubair Ahmed Laghari, Pin Nie, Qian Gao, Hai Xia Xie
      Type III secretion system (T3SS) is a large macromolecular assembly found at the surface of many pathogenic Gram-negative bacteria. Edwardsiella tarda is an important Gram-negative pathogen that employs T3SS to deliver effectors into host cells to facilitate its survival and replication. EseB, EseC, and EseD, when secreted, form a translocon complex on host membranes through which effectors are translocated. The orf19 gene (esaE) of E. tarda is located upstream of esaK, and downstream of esaJ, esaI, esaH and esaG in the T3SS gene cluster. When its domains were searched using Delta-Blast, the EsaE protein was found to belong to the T3SS YscJ/PrgK family. In the present study, it is found that EsaE is not secreted into culture supernatants, and the deletion of esaE abolished the secretion of T3SS translocon protein EseBCD and T3SS effector EseG. Increased steady-state protein level of EseC and EseD was detected in bacterial pellet of ΔesaE strain although a reduced level was observed for the eseC and eseD transcription. EsaE was found to localize in membrane but not the cytoplasm of E. tarda by fractionation. In blue gourami fish infection model, 87.88% of blue gourami infected with ΔesaE strain survived whereas only 3.03% survived when infected with wild-type strain. Taken together, our study demonstrated that EsaE is probably an apparatus protein of T3SS, which contributes to the pathogenesis of E. tarda in fish.


      PubDate: 2016-05-16T14:19:26Z
       
  • Leptospira interrogans serovars Bratislava and Muenchen animal infections:
           Implications for epidemiology and control
    • Abstract: Publication date: Available online 12 May 2016
      Source:Veterinary Microbiology
      Author(s): Z. Arent, C. Frizzell, C. Gilmore, A. Allen, W.A. Ellis
      Strains of Leptospira interrogans belonging to two very closely related serovars − Bratislava and Muenchen − have been associated with disease in domestic animals, in particular pigs, but also in horses and dogs. Similar strains have also been recovered from various wildlife species. Their epidemiology is poorly understood. Two hundred and forty seven such isolates, from UK domestic animal and wildlife species, were examined by restriction endonuclease analysis in an attempt to elucidate their epidemiology. A representative sub-sample of 65 of these isolates was further examined by multiple-locus variable-number tandem repeat analysis and 22 by secY sequencing. Ten restriction pattern types were identified. The majority of isolates fell into one of three restriction endonuclease analysis pattern types designated B2a, B2b and M2a. B2a was ubiquitous and was isolated from 10 species and represented the majority of the horse and all dog isolates. B2b was very different, being isolated only from pigs, indicating that this type was maintained by pigs. The pattern M2a was reported for the majority of isolates from pigs but also was common in small rodents isolates. Five restriction pattern types were found only in wildlife suggesting that they are unlikely to pose a disease threat to domestic animals. Multiple-locus variable-number tandem repeat analysis identified six clusters. The REA types B2a and B2b were all found in one MLVA cluster while the majority of the M2a strains examined occurred in another cluster. The secY sequencing detected only one sequence type, clustered with other serovars of Leptospira interrogans.


      PubDate: 2016-05-16T14:19:26Z
       
  • Isolation and confirmation of viral nervous necrosis (VNN) disease in
           golden grey mullet (Liza aurata) and leaping mullet (Liza saliens) in the
           Iranian waters of the Caspian Sea
    • Abstract: Publication date: Available online 14 May 2016
      Source:Veterinary Microbiology
      Author(s): M.E.J. Zorriehzahra, M. Ghasemi, M. Ghiasi, S.H. Karsidani, G. Bovo, A. Nazari, M. Adel, V. Arizza, K. Dhama
      The present study was conducted on 428 moribund mullet fish samples to isolate and identify the causative agent of a mysterious acute mortality which recently occurred in wild mullets in Iranian waters of Caspian Sea, suspected to be due to viral nervous necrosis (VNN) disease. Disease investigation was carried out employing various diagnostic procedures such as virology, bacteriology, parasitology, hematology, histopathology, IFAT, IHC and nested RT-PCR. Brain and eye samples of affected fishes were collected in sterile conditions and then kept at −80° C for cell culture isolation and nested RT-PCR detection of the causative agent. Other tissue samples were also collected and fixed for histopathology, IHC and EM examinations. CPE was observed in cell cultures at 6days after inoculation. Nine samples were found positive with virological assay. Nested RT-PCR, performed on suspected tissues and CPE positive samples, showed that about 21 tissue samples and all the CPE positive samples were positive for VNN virus (VNNV). IFAT was selected as a confirmatory method for detecting the presence of Betanodavirus antigen, cell culture isolation results and nested RT-PCR findings. Moreover, VNNV particles with 25–30nm in diameter were also visualized in the infected brain and retina. In pathogenicity studies, guppy fishes bathed in VNNV-infected tissue culture (10−4 TCID50) showed clinical signs similar to naturally infected mullet after 15days post infection (dpi), with mortality rates reaching up to 100% at 30 dpi. Affected organ samples as examined by cell culture isolation, IFAT, IHC and histopathology, revealed the presence of VNNV in the guppy fishes. In conclusion, it was confirmed that VNNV was the main causative agent for the disease outbreak in mullet fish in the Caspian Sea, and this is such first report from Iran.


      PubDate: 2016-05-16T14:19:26Z
       
  • Spread and persistence of VIM-1 Carbapenemase-producing Enterobacteriaceae
           in three German swine farms in 2011 and 2012
    • Abstract: Publication date: Available online 7 May 2016
      Source:Veterinary Microbiology
      Author(s): Jennie Fischer, Mateo San José, Nicole Roschanski, Silvia Schmoger, Beatrice Baumann, Alexandra Irrgang, Anika Friese, Uwe Roesler, Reiner Helmuth, Beatriz Guerra
      The occurrence of carbapenemase-producing Enterobacteriaceae in livestock is considered as a threat for public health. In Germany, VIM-1-producing Escherichia (E.) coli sequence type (ST) 88 and Salmonella Infantis isolates harbouring bla VIM-1 IncHI2 plasmids have been isolated from swine and poultry farms. A retrospective study was performed to determine if there was a broader distribution of VIM-1-positive isolates in any of the carbapenemase-positive swine farms. Selective incubation (carbapenem-containing broth) of 249 conserved cultures collected in three farms (2011–2012), allowed the detection of 40 bla VIM-1-positive isolates. Apart from the already known non-motile Salmonella Infantis isolate R25 (farm S1) and R27 (S2), a third isolate was recovered from farm S3. For E. coli, additional to isolates R29 and R178 (S2), 35 new isolates were identified in the same farm during all the sampling periods (three dates, 2011) and in samples from different animals, farm environment, manure and flies. The newly identified E. coli and Salmonella isolates showed similar genetic and phenotypic characteristics (XbaI-PFGE profiles, antimicrobial resistance patterns, plasmid content, phylogroups, antigenic formula) to those in the previously described strains, suggesting microevolution within the clonal lines within one fattening period. The study shows that persistence of carbapenemase-producing clonal lines in livestock farms is possible, and underlines the need for harmonised monitoring and surveillance to monitor the occurrence of such bacteria in European livestock.


      PubDate: 2016-05-10T14:05:20Z
       
  • Genetic analysis of a Treponema phagedenis locus encoding antigenic
           lipoproteins with potential for antigenic variation
    • Abstract: Publication date: Available online 6 May 2016
      Source:Veterinary Microbiology
      Author(s): Mamoona Mushtaq, Erik Bongcam-Rudloff, Heidur Loftsdottir, Märit Pringle, Bo Segerman, Richard Zuerner, Anna Rosander
      Digital dermatitis (DD) is a painful and debilitating claw disease in cattle. Spirochetes of the genus Treponema are found in high numbers in the lesions and are likely to be involved in the pathogenesis. The occurrence of Treponema phagedenis in DD lesions, especially near the interface of healthy and diseased tissue, suggests that this species contributes to the development and/or progression of the lesions. In this study we characterized a genetic locus in T. phagedenis that contains coding regions for three antigenic proteins, PrrA, VpsA, and VpsB. Comparative analysis of homologous loci from fifteen strains suggests that prrA may be transposed into or out of this locus. Alterations in the copy number of TA repeats within the putative promoter region may regulate VpsA/B expression. The vpsA and prrA genes occur in allelic variants in different T. phagedenis isolates and may provide one explanation for the antigenic variation observed in T. phagedenis DD isolates.


      PubDate: 2016-05-06T14:43:18Z
       
  • National reduction in porcine circovirus type 2 prevalence following
           introduction of vaccination
    • Abstract: Publication date: Available online 3 May 2016
      Source:Veterinary Microbiology
      Author(s): Cheryl M.T. Dvorak, Yan Yang, Charles Haley, Nikita Sharma, Michael P. Murtaugh
      Porcine circovirus type 2 (PCV2), a small, single-stranded circular DNA virus and the causative agent of porcine circovirus associated disease (PCVAD), was first observed in the mid-1990s in pigs with a post-weaning wasting disease. In 2006 the number of PCVAD cases greatly increased, marking it as an important viral pathogen for the United States (US) swine industry. PCV2 vaccines were introduced to the US in 2006 in response to widespread outbreaks of PCVAD. These vaccines were effective in preventing disease, but did not eliminate virus from the animals. In 2006, prior to vaccine use, a study of PCV2 prevalence in pig herds across the US was performed in conjunction with the US National Animal Health Monitoring System. In 2012, 6 years after widespread PCV2 vaccination, this study was repeated. Since the introduction of PCV2 vaccines in 2006, viral presence and viral loads have greatly decreased, and a genotypic shift dominated by PCV2b has occurred. Antibody levels have decreased in the pig population, but approximately 95% of sites continue to be antibody-positive. Widespread vaccination has controlled PCVAD and decreased PCV2 prevalence to the point that viremia is not detected on many sites. Thus, continued vaccination may lead to PCV2 elimination in the national herd over time.


      PubDate: 2016-05-06T14:43:18Z
       
  • The Chinese highly pathogenic porcine reproductive and respiratory
           syndrome virus infection suppresses Th17 cells response in vivo
    • Abstract: Publication date: Available online 3 May 2016
      Source:Veterinary Microbiology
      Author(s): Long Zhang, Lei Zhou, Xinna Ge, Xin Guo, Jun Han, Hanchun Yang
      Porcine reproductive and respiratory syndrome virus (PRRSV) has been shown to immunomodulate innate and adaptive immunity of pigs. The Chinese highly pathogenic PRRSV (HP-PRRSV) infection causes severe bacterial secondary infection in pigs. However, the mechanism in relation to the bacterial secondary infection induced by HP-PRRSV remains unknown. In the present study, Th17 cells response in peripheral blood, lungs, spleens and lymph nodes of piglets were analyzed, and bacterial loads in lungs of piglets were examined upon HP-PRRSV infection. Meanwhile the changes of CD4+ and CD8+ T cells in peripheral blood of the inoculated piglets were analyzed. The results showed that HP-PRRSV-inoculated piglets exhibited a suppressed Th17 cells response in peripheral blood and a reduced number of Th17 cells in lungs, and higher bacterial loads in lungs, compared with low pathogenic PRRSV. Moreover, HP-PRRSV obviously resulted in severe depletion of porcine T cells in peripheral blood at the early stage of infection. These findings indicate that HP-PRRSV infection suppresses the response of Th17 cells that play an important role in combating bacterial infections, suggesting a possible correlation between the suppression of Th17 cells response in vivo and bacterial secondary infection induced by HP-PRRSV. Our present study adds a novel insight into better understanding of the pathogenesis of the Chinese HP-PRRSV.


      PubDate: 2016-05-06T14:43:18Z
       
  • IFC - Aims & Scope, EDB, Publication Information
    • Abstract: Publication date: 30 May 2016
      Source:Veterinary Microbiology, Volume 188




      PubDate: 2016-05-02T14:30:25Z
       
  • Detection of bovine papillomavirus type 14 DNA sequences in urinary
           bladder tumors in cattle
    • Abstract: Publication date: Available online 27 April 2016
      Source:Veterinary Microbiology
      Author(s): Sante Roperto, John S. Munday, Federica Corrado, Maria Goria, Franco Roperto
      Bovine papillomavirus type 14 (BPV-14) is a novel Deltapapillomavirus (δPV) which is most closely related to BPV-1, -2, and -13, well-known members of the δPV genus. So far BPV-14 has been detected in cutaneous neoplastic lesions in cattle and in feline sarcoids. As BPV-14 may share biological and pathological properties with BPV-1, -2 and -13, it has been hypothesized that, like other δPVs, BPV-14 could be associated with bovine bladder neoplasia. In this study, 50 tumors of the urinary bladder of cattle were diagnosed. DNA was extracted from all tumor samples as well as from 25 normal bladder samples and submitted to BPV-14 L1 PCR and subsequent amplicon sequencing analysis. BPV-14 L1 DNA sequences of specific 195bp amplicons were obtained from 17 of 50 (34%) tumor DNA isolates; no BPV-14 DNA was detected from 25 normal samples. Amplicons revealed a 99% homology with the corresponding BPV-14 L1 DNA region (GenBank accession number KP276343.1). Co-infections by two or three δPV types were also seen. This study reveals the presence of BPV-14 DNA alone or in combination with other δPV DNA in bovine bladder tumors alone and suggests that BPV-14 could also be involved in bladder neoplasia as its E5 oncoprotein has the potential to induce cell proliferation. Furthermore, this is the first study to show the presence of BPV-14 in Europe, suggesting that BPV-14, like other δPVs, has a worldwide distribution.


      PubDate: 2016-05-02T14:30:25Z
       
  • Detection and characterization of extended-spectrum
           β-lactamase-producing Escherichia coli from chicken production chains
           in Nigeria
    • Abstract: Publication date: Available online 27 April 2016
      Source:Veterinary Microbiology
      Author(s): Olufemi E. Ojo, Stefan Schwarz, Geovana B. Michael
      A total of 405 Escherichia coli from the chicken production chains in Nigeria were investigated for ESBL-production and 4 isolates were identified as ESBL producers. They were characterized by XbaI-PFGE, multilocus sequence typing (MLST), phylotyping, sequencing of porin and regulatory genes and of the regulatory region of chromosomal ampC genes. Transformed ESBL gene-carrying plasmids were characterized by S1-nuclease, replicon typing, conjugation, digestion and PCRs for detection of the genetic environment of ESBL genes. Susceptibility testing, PCRs for the resistance genes, integrons, and the DNA microarray were performed with both, the original isolates and the transformants. All ESBL-producing isolates harboured bla CTX-M-15 genes located on non-conjugative plasmids (120–155kb). Three isolates with closely related/indistinguishable XbaI-patterns belonged to phylogroup A, and MLST sequence type ST10 and the fourth to phylogroup D and ST405. Resistance to aminoglycosides, sulfonamides/trimethoprim, quinolones, and tetracyclines were seen in all isolates. Incompatibility group IncFIB bla CTX-M-15-carrying plasmids were detected in the three related isolates which carried also a class 1 integron (aadA2-orfF-dfrA12) and the resistance genes bla OXA-1, bla TEM-1, aac(3′)-IIa, aac(6′)-Ib-cr, sul1, sul2, and tet(A). The IncFIA-IncFIB-IncI1 bla CTX-M-15-carrying plasmid harboured additionally the resistance genes aac(3′)-IIa and tet(B). The bla CTX-M-15 genes were associated with ISEcp1 and Δorf477. ESBL-producing isolates showed elevated MICs to cefoxitin (16–64mg/L) and ertapenem MICs (0.5-2.0mg/L) mainly due to alterations in the porin genes. The virulence genes astA and prfB were detected. Although a low prevalence of ESBL-producing isolates was found, co-located resistance genes on the ESBL gene-carrying plasmids may facilitate the dissemination of them.


      PubDate: 2016-05-02T14:30:25Z
       
  • Antibiotic resistance profiles of coagulase-negative staphylococci in
           livestock environments
    • Abstract: Publication date: Available online 30 April 2016
      Source:Veterinary Microbiology
      Author(s): Sonja M.K. Schoenfelder, Ying Dong, Andrea T. Feßler, Stefan Schwarz, Christoph Schoen, Robin Köck, Wilma Ziebuhr
      Livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) have globally emerged in animal husbandry. In addition to methicillin resistance, LA-MRSA may carry a variety of novel and uncommon antimicrobial resistance genes. Occurrence of the same resistance genes in coagulase-negative staphylococci (CoNS) and S. aureus suggests an ongoing genetic exchange between LA-MRSA and other staphylococci whose driving forces in the ecological niche of the farm environment are, however, still poorly understood. To assess the potential of CoNS as putative reservoirs for antibiotic resistance genes, we analysed the antimicrobial susceptibility of CoNS from dust and manure samples obtained in 41 pig farms in Germany, most of them (36 of 41) with a proven LA-MRSA/MSSA history. Among the 344 isolates analysed, 18 different CoNS species were identified and S. sciuri represented the most prevalent species (46%). High resistance rates were detected for tetracycline (71%), penicillin (65%) and oxacillin (64%) as well as fusidic acid (50%), which was mainly due to reduced susceptibility among S. sciuri isolates. S. sciuri exhibited pronounced multiresistance, and many isolates were characterised by the carriage of a number of uncommon (multi)resistance genes (e.g. cfr, apmA, fexA) and decreased susceptibility towards last resort antibiotics such as linezolid and daptomycin. The combined data suggest that S. sciuri harbours a significant resistance gene pool that requires further attention. We hypothesise that members of this species, due to their flexible lifestyle, might contribute to the spread of such genes in livestock environments.


      PubDate: 2016-05-02T14:30:25Z
       
  • Antimicrobial susceptibility of Mycoplasma bovis isolates from veal calves
           and dairy cattle in the Netherlands
    • Abstract: Publication date: 30 June 2016
      Source:Veterinary Microbiology, Volume 189
      Author(s): Annet Heuvelink, Constance Reugebrink, Jet Mars
      Control of Mycoplasma bovis infections depends on good husbandry practices and antibiotic treatment. To allow more prudent use of antimicrobial drugs, there is a need for information on the susceptibility profile of this pathogen. The objective of the present study was to analyse the in vitro antimicrobial susceptibility of clinical M. bovis isolates in the Netherlands. The collection comprised 95 bovine isolates, originating from lungs (n=56), mastitis milk (n =27), and synovial fluid (n =12), collected between 2008 and 2014. Minimal inhibitory concentrations (MICs) were assessed by broth microdilution, both by using in-house prepared MIC plates and by using commercially available MIC plates. For each antimicrobial agent, the range of MIC results, the MIC50, and MIC90 values were calculated. M. bovis strains recently isolated in the Netherlands appeared to be characterized by relatively high MIC values for antimicrobial agents that, until now, have been recommended by the Dutch Association of Veterinarians for treating pneumonia caused by Mycoplasma species. Fluoroquinolones appeared to be the most efficacious in inhibiting M. bovis growth, followed by tulathromycin and oxytetracycline. The highest MIC values were obtained for erythromycin, tilmicosin, and tylosin. Future studies should be done on determining M. bovis specific clinical breakpoints, standardization of methods to determine MIC values as well as molecular studies on detection of antimicrobial resistance mechanisms of M. bovis isolates to develop PCR assays for determining resistance.


      PubDate: 2016-04-27T14:16:54Z
       
  • Aerosol transmission of foot-and-mouth disease virus Asia-1 under
           experimental conditions
    • Abstract: Publication date: Available online 26 April 2016
      Source:Veterinary Microbiology
      Author(s): C. Colenutt, J.L. Gonzales, D.J. Paton, J. Gloster, N. Nelson, C. Sanders
      Foot-and-mouth disease virus (FMDV) control measures rely on understanding of virus transmission mechanisms. Direct contact between naïve and infected animals or spread by contaminated fomites is prevented by quarantines and rigorous decontamination procedures during outbreaks. Transmission of FMDV by aerosol may not be prevented by these control measures and this route of transmission may allow infection of animals at distance from the infection source. Understanding the potential for aerosol spread of specific FMDV strains is important for informing control strategies in an outbreak. Here, the potential for transmission of an FMDV Asia 1 strain between pigs and cattle by indirect aerosol exposure was evaluated in an experimental setting. Four naïve calves were exposed to aerosols emitted from three infected pigs in an adjacent room for a 10h period. Direct contact between pigs and cattle and fomite transfer between rooms was prevented. Viral titres in aerosols emitted by the infected pigs were measured to estimate the dose that calves were exposed to. One of the calves developed clinical signs of FMD, whilst there was serological evidence for spread to cattle by aerosol transmission in the remaining three calves. This highlights the possibility that this FMDV Asia 1 strain could be spread by aerosol transmission given appropriate environmental conditions should an outbreak occur in pigs. Our estimates suggest the exposure dose required for aerosol transmission was higher than has been previously quantified for other serotypes, implying that aerosols are less likely to play a significant role in transmission and spread of this FMDV strain.


      PubDate: 2016-04-27T14:16:54Z
       
  • Low pathogenic avian influenza (H9N2) in chicken: Evaluation of an
           ancestral H9-MVA vaccine
    • Abstract: Publication date: Available online 26 April 2016
      Source:Veterinary Microbiology
      Author(s): Mariette F. Ducatez, Jens Becker, Astrid Freudenstein, Maxence Delverdier, Mattias Delpont, Gerd Sutter, Jean-Luc Guérin, Asisa Volz
      Modified Vaccinia Ankara (MVA) has proven its efficacy as a recombinant vector vaccine for numerous pathogens including influenza virus. The present study aimed at evaluating a recombinant MVA candidate vaccine against low pathogenic avian influenza virus subtype H9N2 in the chicken model. As the high genetic and antigenic diversity of H9N2 viruses increases vaccine design complexity, one strategy to widen the range of vaccine coverage is to use an ancestor sequence. We therefore generated a recombinant MVA encoding for the gene sequence of an ancestral hemagglutinin H9 protein (a computationally derived amino acid sequence of the node of the H9N2 G1 lineage strains was obtained using the ANCESCON program). We analyzed the genetics and the growth properties of the MVA vector virus confirming suitability for use under biosafety level 1 and tested its efficacy when applied either as an intra-muscular (IM) or an oral vaccine in specific pathogen free chickens challenged with A/chicken/Tunisia/12/2010(H9N2). Two control groups were studied in parallel (unvaccinated and inoculated birds; unvaccinated and non-inoculated birds). IM vaccinated birds seroconverted as early as four days post vaccination and neutralizing antibodies were detected against A/chicken/Tunisia/12/2010(H9N2) in all the birds before challenge. The role of local mucosal immunity is unclear here as no antibodies were detected in eye drop or aerosol vaccinated birds. Clinical signs were not detected in any of the infected birds even in absence of vaccination. Virus replication was observed in both vaccinated and unvaccinated chickens, suggesting the MVA-ancestral H9 vaccine may not stop virus spread in the field. However vaccinated birds showed less histological damage, fewer influenza-positive cells and shorter virus shedding than their unvaccinated counterparts.


      PubDate: 2016-04-27T14:16:54Z
       
  • The serine protease autotransporter Tsh contributes to the virulence of
           Edwardsiella tarda
    • Abstract: Publication date: Available online 25 April 2016
      Source:Veterinary Microbiology
      Author(s): Yong-hua Hu, Hai-zhen Zhou, Qian-wen Jin, Jian Zhang
      The temperature-sensitive hemagglutinin (Tsh), identified as serine protease autotransporters of the Enterobacteriaceae (SPATEs) proteins, is an important virulence factor for avian-pathogenic Escherichia coli (APEC) and uropathogenic E. coli. However, little is known about the role of Tsh as a virulence factor in Edwardsiella tarda, a severe fish pathogen. In this study, we characterized the Tsh of E. tarda (named TshEt) and examined its function and vaccine potential. TshEt is composed of 1,224 residues and has three functional domains typical for autotransporters. Quantitative real-time reverse transcriptase-PCR analysis showed that expression of tshEt was upregulated under conditions of high temperature, increased cell density, high pH, and iron starvation and during the infection of host cells. A markerless tsh in-frame mutant strain, TX01Δtsh, was constructed to determine whether TshEt participates in the pathogenicity of E. tarda, Compared to the wild type TX01, TX01Δtsh exhibited (i) retarded biofilm growth, (ii) decreased resistance against serum killing, (iii) impaired ability to block the host immune response, (iv) attenuated tissue and cellular infectivity. Introduction of a trans-expressed tsh gene restored the lost virulence of TX01Δtsh. The passenger domain of TshEt contains a putative serine protease (PepS) that exhibits apparent proteolytic activity when expressed in and purified from E. coli as a recombinant protein (rPepS). When used as a subunit vaccine to immunize Japanese flounder, rPepS was able to induce effective immune protection. This is the first study of Tsh in a fish pathogen, and the results suggest that TshEt exerts pleiotropic effects on the pathogenesis of E. tarda.


      PubDate: 2016-04-27T14:16:54Z
       
  • Genome-wide mining of potential virulence-associated genes in Riemerella
           anatipestifer using random transposon mutagenesis
    • Abstract: Publication date: Available online 26 April 2016
      Source:Veterinary Microbiology
      Author(s): Xintao Ni, Pan Jiang, Linlin Xing, Changcan Ou, Hui Yu, Jingjing Qi, Bingqing Sun, Junsheng Cui, Guijun Wang, Qinghai Hu
      Riemerella anatipestifer infection is a severe disease confronting the duck industry worldwide. However, little is known about the molecular basis of R. anatipestifer pathogenesis. In this study, we screened 3580 transposon Tn4351 insertion mutagenesis mutants of the highly virulent strain YZb1 in a duckling infection experiment and found 29 of them to be attenuated and 28 potential virulence-associated genes were identified. Molecular characterization of transposon insertion sites showed that of the 28 screened genes, two were predicted to encode TonB-dependent outer membrane receptor (plugs), sixteen encoded enzymes, and seven encoded hypothetical proteins. In addition, of the 28 affected genes, 19 were only found in bacteria belonging to the phylum Bacteroidetes and 10 were only found in the family Flavobacteriaceae. The median lethal dose of the mutants M11 and M29, which was affected in Riean_0060 and Riean_1537 respectively, were about 1700-fold and 210-fold higher than that of the wild-type strain YZb1, and those of the complemented strains M11(pRES-Riean_0060) and M29(pRES-Riean_1537) were decreased by 25- and 3-fold respectively compared to those of the mutants M11 and M29. Additional analysis indicated that the blood bacterial loading of ducklings infected with M11 or M29 was decreased significantly, as compared with that in ducklings infected with the wild-type strain YZb1. Thus, our results indicate that Riean_0060 and Riean_1537 were involved in R. anatipestifer pathogenesis.


      PubDate: 2016-04-27T14:16:54Z
       
  • Evolution of equine infectious anaemia in naturally infected mules with
           different serological reactivity patterns prior and after immune
           suppression
    • Abstract: Publication date: 30 June 2016
      Source:Veterinary Microbiology, Volume 189
      Author(s): Gian Luca Autorino, Claudia Eleni, Giuseppe Manna, Raffaele Frontoso, Roberto Nardini, Cristiano Cocumelli, Francesca Rosone, Andrea Caprioli, Lavinia Alfieri, Maria Teresa Scicluna
      Information on equine infectious anaemia (EIA) in mules, including those with an equivocal reaction in agar gel immunodiffusion test (AGIDT), is scarce. For this, a study was conducted to evaluate the clinical, viral loads and pathological findings of two groups of naturally infected asymptomatic mules, respectively with a negative/equivocal and positive AGIDT reactivity, which were subjected to pharmacological immune suppression (IS). A non-infected control was included in the study that remained negative during the observation period. Throughout the whole study, even repeated episodes of recrudescence of EIA were observed in 9 infected mules, independently from their AGIDT reactivity. These events were generally characterised by mild, transient alterations, typical of the EIA acute form represented by hyperthermia and thrombocytopenia, in concomitance with viral RNA (vRNA) peaks that were higher in the Post-IS period, reaching values similar to those of horses during the clinical acute phase of EIA. Total tissue viral nucleic acid loads were greatest in animals with the major vRNA activity and in particular in those with negative/equivocal AGIDT reactivity. vRNA replication levels were around 10–1000 times lower than those reported in horses, with the animals still presenting typical alterations of EIA reactivation. Macroscopic lesions were absent in all the infected animals while histological alterations were characterised by lymphomonocyte infiltrates and moderate hemosiderosis in the cytoplasm of macrophages. On the basis of the above results, even mules with an equivocal/negative AGIDT reaction may act as EIAV reservoirs. Moreover, such animals could escape detection due to the low AGIDT sensitivity and therefore contribute to the maintenance and spread of the infection.


      PubDate: 2016-04-27T14:16:54Z
       
  • Colonization with methicillin-resistant Staphylococcus pseudintermedius in
           multi-dog households: A longitudinal study using whole genome sequencing
    • Abstract: Publication date: 30 June 2016
      Source:Veterinary Microbiology, Volume 189
      Author(s): Ulrika Windahl, Joakim Ågren, Bodil S. Holst, Stefan Börjesson
      Despite a worldwide increase in the presence of methicillin-resistant Staphylococcus pseudintermedius (MRSP) in dogs and its potential to cause serious canine health problem, the understanding of the transmission and long-term carriage of MRSP is limited. The objective of this study was to investigate the transmission of MRSP to contact dogs living in multiple dog households where one or more of the dogs had been diagnosed with a clinically apparent infection with MRSP. MRSP carriage was investigated over several months in 11 dogs living in four separate multiple dog households where an MRSP infection in a dog had been diagnosed. Whole-genome sequencing was used for genotypic characterization. Contact dogs were only MRSP-positive if the index dog was positive on the same sample occasion. Three contact dogs were consistently MRSP-negative. The data from whole genome sequencing showed similarities between isolates within each family group, indicating that MRSP was transmitted within each family. The results show that the risk of MRSP-colonization in dogs living with an MRSP-infected dog is reduced if the index dog becomes MRSP negative. All of the contact dogs will not carry MRSP continuously during the time the index dog is MRSP-positive. The information yielded from whole genome sequencing showed the methodology to be a promising additional tool in epidemiologic investigations of MRSP transmission.


      PubDate: 2016-04-27T14:16:54Z
       
  • The first experimental research on the pathogenicity of Arcobacter
           butzleri in zebrafish
    • Abstract: Publication date: Available online 22 April 2016
      Source:Veterinary Microbiology
      Author(s): Mehmet Nuri Açik, Hayati Yüksel, Aykut Ulucan, Burhan Çetinkaya
      This experimental study was conducted to investigate the pathogenicity and histopathology of Arcobacter butzleri in zebrafish model organism. Firstly, mean infective dose (ID50) of A. butzleri was calculated in zebrafish as 1.3×108 CFU/mL and 1×105 CFU/mL by immersion and intraperitoneal injection, respectively. For histopathological trials, the ID50 of A. butzleri were given to zebrafish by both immersion and intraperitoneal routes and then, clinical and pathological findings were evaluated on days 1, 3, 5, 7 and 21 of the experiment. During the experimental period, no clinical signs or gross lesions of disease were observed in the zebrafish groups infected with the ID50 of A. butzleri by either method. In the histopathological examination, acute inflammation characterized by neutrophil and plasma cells and local necrosis or congestion were determined in liver, kidney, spleen, gaster and other visceral organs. In addition peritonitis, leukocyte infiltration, villous atrophy and septicemia were observed in the experimental groups. Neither gross nor microscopic lesions were detected in the control groups. This study presented the first report of experimental A. butzleri infection in wild zebrafish. In the light of the findings obtained here, it was concluded that zebrafish could be used as a model organism to investigate pathogenicity and histopathology of arcobacters.


      PubDate: 2016-04-23T13:54:59Z
       
  • Lineage associated expression of virulence traits in bovine-adapted
           Staphylococcus aureus
    • Abstract: Publication date: Available online 21 April 2016
      Source:Veterinary Microbiology
      Author(s): Kathleen E. Budd, Jennifer Mitchell, Orla M. Keane
      Bovine mastitis is the most costly disease to the dairy industry worldwide with Staphylococcus aureus commonly associated with intramammary infections that are persistent and refractory to treatment. The strains of S. aureus that cause mastitis predominantly belong to a number of well-described bovine-adapted lineages. The objective of this study was to determine if a variety of potential virulence traits were associated with lineage. Bovine-adapted S. aureus isolates (n=120), belonging to lineages CC97, CC151 and ST136, were tested for their ability to adhere to and internalise within cultured bovine mammary epithelial cells (bMEC), to bind bovine fibronectin, to form a biofilm in TSB, TSB+1% glucose and TSB+4% NaCl, and to induce an immune response from bMEC. There were no significant differences between the lineages in ability to adhere to or internalise within bMEC although there were significant differences between individual isolates. For lineages CC97 and ST136, mammalian cell adherence was correlated with the ability to bind bovine fibronectin, however isolates from CC151 could not bind bovine fibronectin in vitro, but adhered to bMEC in a fibronectin-independent manner. There were significant differences between the lineages in ability to form a biofilm in all three growth media with ST136 forming the strongest biofilm while CC151 formed the weakest biofilm. Lineages also differed in their ability to elicit an immune response from bMEC with CC97 eliciting a stronger immune response than CC151 and ST136. These data indicate the potential for both lineage and strain-specific virulence and a strain-specific response to infection in vivo and caution against extrapolating an effect from a single strain of S. aureus to draw conclusions regarding virulence or the host response to infection in unrelated lineages.


      PubDate: 2016-04-23T13:54:59Z
       
  • Determining the optimal number of individual samples to pool for
           quantification of average herd levels of antimicrobial resistance genes in
           Danish pig herds using high-throughput qPCR
    • Abstract: Publication date: Available online 22 April 2016
      Source:Veterinary Microbiology
      Author(s): Julie Clasen, Anders Mellerup, John Elmerdahl Olsen, Øystein Angen, Anders Folkesson, Tariq Halasa, Nils Toft, Anna Camilla Birkegård
      The primary objective of this study was to determine the minimum number of individual fecal samples to pool together in order to obtain a representative sample for herd level quantification of antimicrobial resistance (AMR) genes in a Danish pig herd, using a novel high-throughput qPCR assay. The secondary objective was to assess the agreement between different methods of sample pooling. Quantification of AMR was achieved using a high-throughput qPCR method to quantify the levels of seven AMR genes (ermB, ermF, sulI, sulII, tet(M), tet(O) and tet(W)). A large variation in the levels of AMR genes was found between individual samples. As the number of samples in a pool increased, a decrease in sample variation was observed. It was concluded that the optimal pooling size is five samples, as an almost steady state in the variation was observed when pooling this number of samples. Good agreement between different pooling methods was found and the least time-consuming method of pooling, by transferring feces from each individual sample to a tube using a 10μl inoculation loop and adding 3.5ml of PBS, approximating a 10% solution, can therefore be used in future studies.


      PubDate: 2016-04-23T13:54:59Z
       
  • Thymic depletion of lymphocytes is associated with the virulence of
           PRRSV-1 strains
    • Abstract: Publication date: 30 May 2016
      Source:Veterinary Microbiology, Volume 188
      Author(s): Shyrley Paola Amarilla, Jaime Gómez-Laguna, Librado Carrasco, Irene M. Rodríguez-Gómez, José M. Caridad y Ocerín, Simon P. Graham, Jean-Pierre Frossard, Falko Steinbach, Francisco J. Salguero
      Porcine reproductive and respiratory syndrome virus (PRRSV) exists as two distinct viruses, type 1 (PRRSV-1) and type 2 (PRRSV-2). Atrophy of the thymus in PRRSV-2 infected piglets has been associated with a loss of thymocytes. The present study aimed to evaluate the impact of PRRSV-1 strains of differing virulence on the thymus of infected piglets by analysing the histomorphometry, the presence of apoptotic cells and cells producing cytokines. Thymic samples were taken from animals experimentally infected (with LV, SU1-bel, and 215-06 strains) or mock inoculated animals at 3, 7 and 35days post-infection (dpi) and processed for histopathological and immunohistochemical analyses. PRRSV antigen was detected in the thymus from 3dpi until the end of the study in all virus-infected animals with the highest numbers of infected cells detected in SU1-bel group. The histomorphometry analysis and counts of CD3+ thymocytes in the thymic cortex displayed significant differences between strains at different time-points (p ≤0.011), with SU1-bel group showing the most severe changes at 7dpi. Cell death displayed statistically significant increase in the cortex of all infected animals, with SU1-bel group showing the highest rate at 3 and 7dpi. The number of cells immunostained against IL-1α, TNF-α and IL-10 were predominantly detected in the medulla (p ≤0.01). An increase in the number of TNF-α and IL-10 positive cells was observed in LV and SU-1bel groups. Our results demonstrate that different PRRSV-1 strains induced depletion of the thymic cortex due to apoptosis of thymocytes and that the most severe depletion was associated with the highly virulent SU1-bel strain.


      PubDate: 2016-04-19T17:46:02Z
       
  • Chloroquine inhibits Rhodococcus equi replication in murine and foal
           alveolar macrophages by iron-starvation
    • Abstract: Publication date: 30 May 2016
      Source:Veterinary Microbiology, Volume 188
      Author(s): Leticia T. Gressler, Angela I. Bordin, Cole M. McQueen, Noah D. Cohen, Agueda Castagna de Vargas
      Rhodococcus equi preferentially infects macrophages causing pyogranulomatous pneumonia in young foals. Both the vapA and rhbC genes are up-regulated in an iron (Fe)-deprived environment, such as that found within macrophages. Chloroquine (CQ) is a drug widely used against malaria that suppresses the intracellular availability of Fe in eukaryotic cells. The main objective of this study was to evaluate the ability of CQ to inhibit replication of virulent R. equi within murine (J774A.1) and foal alveolar macrophages (AMs) and to verify whether the mechanism of inhibition could be Fe-deprivation-dependent. CQ effect on R. equi extracellular survival and toxicity to J774A.1 were evaluated. R. equi survival within J774A.1 and foal AMs was evaluated under CQ (10 and 20μM), bovine saturated transferrin (bHTF), and bovine unsaturated transferrin (bATF) exposure. To explore the action mechanism of CQ, the superoxide anion production, the lysozyme activity, as well as the relative mRNA expression of vapA and rhbC were examined. CQ at≤20μM had no effect on R. equi extracellular multiplication and J774A.1 viability. Exposure to CQ significantly and markedly reduced survival of R. equi within J774A.1 and foal AMs. Treatment with bHTF did not reverse CQ effect on R. equi. Exposure to CQ did not affected superoxide anion production or lysozyme activity, however vapA and rhbC expression was significantly increased. Our results reinforce the hypothesis that intracellular availability of Fe is required for R. equi survival, and our initial hypothesis that CQ can limit replication of R. equi in J774A.1 and foal AMs, most likely by Fe starvation.


      PubDate: 2016-04-15T17:12:37Z
       
  • Experimental induced avian E. coli salpingitis: Significant impact of
           strain and host factors on the clinical and pathological outcome
    • Abstract: Publication date: Available online 11 April 2016
      Source:Veterinary Microbiology
      Author(s): Rikke Heidemann Olsen, Ida Cecilie Naundrup Thøfner, Susanne Elisabeth Pors, Jens Peter Christensen
      Several types of Escherichia coli have been associated with extra-intestinal infections in poultry, however, they may vary significantly in their virulence potential. The aim of the present study was to investigate the virulence of five strains of E. coli obtained from different disease manifestations or from the cloacae of a healthy chicken. The virulence potential of the strains were evaluated in an avian experimental model for ascending infections, and experiments were conducted in both layers and broiler breeders. The clinical outcome of infection was highly depending on the challenge strain, however, not significantly reflecting the origin of the strain. In general, broiler breeders had a more severe clinical outcomes of infection compared to layers, but major with-in group diversity was observed for all challenge strains of clinical origin. A single strain of ST95 (phylogroup B2) had a distinct ability to cause disease. Results of the study shows major differences in virulence of different strains of E. coli in ascending infections; however, there was no indication of tissue-specific adaptation, since strains obtained from lesions unrelated to the reproductive system were fully capable of causing experimental infection. In conclusion, the study provides evidence for the clinical outcome of infection with E. coli in poultry is largely influenced by the specific strain as well as individual host factors.


      PubDate: 2016-04-12T13:07:28Z
       
  • Whole genome characterization of a G6P[5] rotavirus A strain isolated from
           a stray cat in Japan
    • Abstract: Publication date: Available online 8 April 2016
      Source:Veterinary Microbiology
      Author(s): Miho Kaneko, Masami Mochizuki, Osamu Nakagomi, Toyoko Nakagomi
      The whole genome of an unusual G6P[5] rotavirus A strain named FRV537, which was isolated from a stray cat in Japan, was characterized to determine its species of origin. The genotype constellation of FRV537 was G6-P[5]-I2-R2-C2-M2-A13-N2- T6-E2-H3. No known feline rotavirus has this genotype constellation; the Japanese equine strain OH-4 is the only known strain that does. While FRV537 shares the same genotype with some feline rotaviruses in all genes except those encoding VP4 and NSP1, none of these genes are closely related to those of known feline rotaviruses. By contrast, G6P[5] is almost exclusively present in bovine rotaviruses. The VP7 and VP4 genes of FRV537 formed a lineage with typical bovine rotaviruses with high bootstrap values. As to the internal capsid and nonstructural gene constellation, three bovine rotavirus strains had a constellation identical to that of FRV537. Moreover, each of the genotypes of FRV537 was found to be a common bovine genotype. In addition to the high nucleotide sequence identities between FRV537 and bovine rotaviruses in each genome segment (≥95%), phylogenetic analysis revealed a close relationship to bovine/artiodactyl rotaviruses. Thus, the molecular and phylogenetic evidence suggests that FRV537 isolated from a stray cat was of bovine rotavirus origin.


      PubDate: 2016-04-12T13:07:28Z
       
  • IFC - Aims & Scope, EDB, Publication Information
    • Abstract: Publication date: 1 May 2016
      Source:Veterinary Microbiology, Volume 187




      PubDate: 2016-04-12T13:07:28Z
       
  • Polarisation of equine pregnancy outcome associated with a maternal MHC
           class I allele: preliminary evidence
    • Abstract: Publication date: Available online 6 April 2016
      Source:Veterinary Microbiology
      Author(s): J.H. Kydd, R. Case, C. Winton, S. MacRae, E. Sharp, S.L. Ricketts, N. Rash, J.R. Newton
      Identification of risk factors which are associated with severe clinical signs can assist in the management of disease outbreaks and indicate future research areas. Pregnancy loss during late gestation in the mare compromises welfare, reduces fecundity and has financial implications for horse owners. This retrospective study focussed on the identification of risk factors associated with pregnancy loss among 46 Thoroughbred mares on a single British stud farm, with some but not all losses involving equid herpesvirus-1 (EHV-1) infection. In a sub-group of 30 mares, association between pregnancy loss and the presence of five common Thoroughbred horse haplotypes of the equine Major Histocompatibility Complex (MHC) was assessed. This involved development of sequence specific, reverse transcriptase polymerase chain reactions and in several mares, measurement of cytotoxic T lymphocyte activity. Of the 46 mares, 10 suffered late gestation pregnancy loss or neonatal foal death, five of which were EHV-1 positive. Maternal factors including age, parity, number of EHV-1 specific vaccinations and the number of days between final vaccination and foaling or abortion were not significantly associated with pregnancy loss. In contrast, a statistically significant association between the presence of the MHC class I B2 allele and pregnancy loss was identified, regardless of the fetus/foal’s EHV-1 status (p=0.002). In conclusion, this study demonstrated a significantly positive association between pregnancy loss in Thoroughbred mares and a specific MHC class I allele in the mother. This association requires independent validation and further investigation of the mechanism by which the mare’s genetic background contributes to pregnancy outcome.


      PubDate: 2016-04-07T21:01:16Z
       
  • Persistent spread of the rmtB 16S rRNA methyltransferase gene among
           Escherichia coli isolates from diseased food-producing animals in China
    • Abstract: Publication date: Available online 6 April 2016
      Source:Veterinary Microbiology
      Author(s): Jing Xia, Jian Sun, Ke Cheng, Liang Li, Liang-Xing Fang, Meng-Ting Zou, Xiao-Ping Liao, Ya-Hong Liu
      A total of 963 non-duplicate E. coli strains isolated from food-producing animals between 2002 and 2012 were screened for the presence of the 16S rRNA methyltransferase genes. Among the positive isolates, resistance determinants to extended spectrum β-lactamases, plasmid-mediated quinolone resistance genes as well as floR and fosA/A3/C2 were detected using PCR analysis. These isolates were further subjected to antimicrobial susceptibility testing, molecular typing, PCR-based plasmid replicon typing and plasmid analysis. Of the 963 E. coli isolates, 173 (18.0%), 3 (0.3%) and 2 (0.2%) were rmtB-, armA- and rmtE- positive strains, respectively. All the 16S rRNA methyltransferase gene-positive isolates were multidrug resistant and over 90% of them carried one or more type of resistance gene. IncF (especially IncFII) and non-typeable plasmids played the main role in the dissemination of rmtB, followed by the IncN plasmids. Plasmids that harbored rmtB ranged in size from 20kb to 340kb. EcoRI-RFLP testing of the 109 rmtB-positive plasmids from different years and different origins suggested that horizontal (among diverse animals) and vertical transfer of IncF, non-typeable and IncN-type plasmids were responsible for the spread of rmtB gene. In summary, our findings highlight that rmtB was the most prevalent 16S rRNA methyltransferase gene, which present persistent spread in food-producing animals in China and a diverse group of plasmids was responsible for rmtB dissemination.


      PubDate: 2016-04-07T21:01:16Z
       
  • Microbiome associations in pigs with the best and worst clinical outcomes
           following co-infection with porcine reproductive and respiratory syndrome
           virus (PRRSV) and porcine circovirus type 2 (PCV2)
    • Abstract: Publication date: 30 May 2016
      Source:Veterinary Microbiology, Volume 188
      Author(s): Megan C. Niederwerder, Crystal J. Jaing, James B. Thissen, Ada Giselle Cino-Ozuna, Kevin S. McLoughlin, Raymond R.R. Rowland
      On a world-wide basis, co-infections involving porcine reproductive and respiratory syndrome virus (PRRSV) and porcine circovirus type 2 (PCV2) are common and contribute to a range of polymicrobial disease syndromes in swine. Both viruses compromise host defenses, resulting in increased susceptibility to infections by primary and secondary pathogens that can affect growth performance as well as increased morbidity and mortality. An experimental population of 95 pigs was co-infected with PRRSV and PCV2. At 70days post-infection (dpi), 20 representative pigs were selected as having the best or worst clinical outcome based on average daily gain (ADG) and the presence of clinical disease. Worst clinical outcome pigs had prolonged and greater levels of viremia as measured by qPCR. Serum, lung and fecal samples collected at 70 dpi were analyzed using a comprehensive DNA microarray technology, the Lawrence Livermore Microbial Detection Array, to detect over 8000 microbes. Bacterial species, such as Bacillus cereus, were detected at a higher rate in the serum of worst performing pigs. At the level of the fecal microbiome, the overall microbial diversity was lower in the worst clinical outcome group. The results reinforce the importance of pathogen load in determining clinical outcome and suggest an important role of microbial diversity as a contributing factor in disease.


      PubDate: 2016-04-07T21:01:16Z
       
  • Lethal dose and clinical signs of Aeromonas hydrophila in Arapaima gigas
           (Arapaimidae), the giant fish from Amazon
    • Abstract: Publication date: Available online 2 April 2016
      Source:Veterinary Microbiology
      Author(s): Marcia K.R. Dias, Luciana S. Sampaio, Aldo A. Proietti-Junior, Eliane T.O. Yoshioka, Dália P. Rodrigues, Anselmo F.R. Rodriguez, Ricardo A. Ribeiro, Fernando E.S.E.D.V. Faria, Rodrigo O.A. Ozório, Marcos Tavares-Dias
      Aeromonas hydrophila is causing substantial economic losses in world aquaculture. This study determined the tolerance limit (LD50-96h) of A. hydrophila in Arapaima gigas, and also investigated the clinical signs after intradermal inoculation. Arapaima gigas fingerlings were inoculated intraperitoneally with 0 (control), 1.0×105, 1.0×106, 1.0×107, 1.0×109 and 1.0×1010 CFU/mL of A. hydrophila for the determination of LD50-96h, which was 1.8×108 CFU/mL. In another trial with intradermal inoculation of 1.8×108 CFU/mL A. hydrophila, there was a 91.6% of mortality between 8–23h, and several clinical signs were found. As follows: depigmentation in the tegument, lesions in the tail and fins, loss of balance, reduction of respiratory movements, hemorrhagic foci, necrotic hemorrhages in the kidney, liver and swim bladder, splenomegaly, ascites in the abdominal cavity and hyperemia, enlargement of the gall bladder, among other clinical signs observed. The results showed that A. gigas has a relative tolerance to A. hydrophila when compared to other Neotropical fish species.


      PubDate: 2016-04-03T20:32:54Z
       
  • Evolution of the nasopharyngeal microbiota of beef cattle from weaning to
           40days after arrival at a feedlot
    • Abstract: Publication date: Available online 26 March 2016
      Source:Veterinary Microbiology
      Author(s): Edouard Timsit, Matthew Workentine, Anthony B. Schryvers, Devin B. Holman, Frank van der Meer, Trevor W. Alexander
      Bovine respiratory disease complex (BRDc) is a major cause of morbidity and mortality in beef cattle. There is recent evidence suggesting that the nasopharyngeal microbiota has a key role in respiratory health and disease susceptibility in cattle. However, there is a paucity of knowledge regarding evolution of the nasopharyngeal microbiota when cattle are most likely to develop BRDc (i.e. from weaning to 40days after arrival at a feedlot). The objective was to describe the evolution of the nasopharyngeal microbiota of beef cattle from weaning to 40days after arrival at a feedlot. Deep nasal swabs (DNS) from 30 Angus-cross steers were collected at weaning, on arrival at a feedlot, and at day 40 after arrival. The DNA was extracted from DNS and the hypervariable region V3 of the 16S rRNA gene was amplified and sequenced (Illumina MiSeq platform). Nasopharyngeal microbiota underwent a profound evolution from weaning to arrival at the feedlot and from arrival to day 40, with the abundance of 92 Operational Taxonomic Units (OTUs) significantly changing over time. Mycoplasma (M. dispar and M. bovirhinis) was the most abundant genus in the nasopharynx, accounting for 53% of the total bacterial population. Because an evolving bacterial community may be less capable of resisting colonization by pathogenic bacteria, the instability of the nasopharyngeal microbiota documented in this study might explain why cattle are most likely to be affected with BRDc during the first weeks after weaning and arrival at a feedlot.


      PubDate: 2016-03-26T19:53:26Z
       
  • A Streptococcus suis LysM domain surface protein contributes to bacterial
           virulence
    • Abstract: Publication date: Available online 25 March 2016
      Source:Veterinary Microbiology
      Author(s): Zongfu Wu, Jing Shao, Haiyan Ren, Huanyu Tang, Mingyao Zhou, Jiao Dai, Liying Lai, Huochun Yao, Hongjie Fan, Dai Chen, Jie Zong, Chengping Lu
      Streptococcus suis (SS) is a major swine pathogen, as well as a zoonotic agent for humans. Numerous factors contribute to SS virulence, but the pathogenesis of SS infection is poorly understood. Here, we show that a novel SS surface protein containing a LysM at the N-terminus (SS9-LysM) contributes to SS virulence. Homology analysis revealed that the amino acid sequence of SS9-LysM from the SS strain, GZ0565, shares 99.8–68.7% identity with homologous proteins from other SS strains and 41.2% identity with Group B Streptococcal protective antigen Sip. Immunization experiments showed that 7 out of 30 mice immunized with recombinant SS9-LysM were protected against challenge with the virulent GZ0565 strain, while all of the control mice died within 48h following bacterial challenge. In mouse infection model, the virulence of the SS9-LysM deletion mutant (ΔSS9-LysM) was reduced compared with the wild-type (WT) strain GZ0565 and SS9-LysM complemented strain. In addition, ΔSS9-LysM was significantly more sensitive to killing by pig blood ex vivo and mouse blood in vivo compared with the WT strain and SS9-LysM complemented strain. In vivo transcriptome analysis in mouse blood showed that the WT strain reduced the expression of host genes related to iron-binding by SS9-LysM. Moreover, the total free iron concentration in blood from infected mice was significantly lower for the ΔSS9-LysM strain compared with the WT strain. Together, our data reveal that SS9-LysM facilitates SS survival within blood by releasing more free iron from the host. This represents a new mechanism of SS pathogenesis.


      PubDate: 2016-03-26T19:53:26Z
       
  • LIVING WITH AVIAN FLU—PERSISTENCE OF THE H5N1 HIGHLY PATHOGENIC
           AVIAN INFLUENZA VIRUS IN EGYPT
    • Abstract: Publication date: Available online 19 March 2016
      Source:Veterinary Microbiology
      Author(s): Kevin Yana Njabo, Linda Zanontian, Basma N. Sheta, Ahmed Samy, Shereen Galal, Frederic Paik Schoenberg, Thomas B Smith
      H5N1 highly pathogenic avian influenza virus (HPAIV) continues to cause mortality in poultry and threaten human health at a panzootic scale in Egypt since it was reported in 2006. While the early focus has been in Asia, recent evidence suggests that Egypt is an emerging epicenter for the disease. Despite control measures, epizootic transmission of the disease continues. Here, we investigate the persistence of HPAIV across wild passerine birds and domestic poultry between 2009 and 2012 and the potential risk for continuous viral transmission in Egypt. We use a new weighted cross J-function to investigate the degree and spatial temporal nature of the clustering between sightings of infected birds of different types, and the risk of infection associated with direct contact with infected birds. While we found no infection in wild birds, outbreaks occurred year round between 2009–2012, with a positive interaction between chickens and ducks. The disease was more present in the years 2010 and 2011 coinciding with the political unrest in the country. Egypt thus continues to experience endemic outbreaks of avian influenza HPAIV in poultry and an increased potential risk of infection to other species including humans. With the current trends, the elimination of the HPAIV infection is highly unlikely without a complete revamp of current policies. The application of spatial statistics techniques to these types of data may help us to understand the characteristics of the disease and may subsequently allow practitioners to explore possible preventive solutions.


      PubDate: 2016-03-21T19:27:23Z
       
  • Highly pathogenic avian influenza viruses H5N2, H5N3, and H5N8 in Taiwan
           in 2015
    • Abstract: Publication date: Available online 19 March 2016
      Source:Veterinary Microbiology
      Author(s): Ming-Shiuh Lee, Li-Hsuan Chen, Yen-Ping Chen, Yu-Pin Liu, Wan-Chen Li, Yeou-Liang Lin, Fan Lee
      A severe epidemic, affecting mainly goose populations, broke out in early January 2015.The causative agents were identified as novel H5 avian influenza viruses carrying N2, N3, and N8 subtypes of the neuraminidase gene. From January 8 to February 11, 766 waterfowl and poultry farms were invaded by the H5 viruses, and more than 2.2 million geese died or were culled. Phylogenetic analysis suggested that these avian influenza viruses derived from the H5 viruses of clade 2.3.4.4 which were emerging in 2014 in East Asia, West Europe, and North America.


      PubDate: 2016-03-21T19:27:23Z
       
  • In vivo virulence of viral haemorrhagic septicaemia virus (VHSV) in
           rainbow trout Oncorhynchus mykiss correlates inversely with in vitro Mx
           gene expression
    • Abstract: Publication date: 1 May 2016
      Source:Veterinary Microbiology, Volume 187
      Author(s): Irene Cano, Bertrand Collet, Clarissa Pereira, Richard Paley, Ronny van Aerle, David Stone, Nick G.H. Taylor
      The in vitro replication of viral haemorrhagic septicaemia virus (VHSV) isolates from each VHSV genotype and the associated cellular host Mx gene expression were analysed. All the isolates were able to infect RTG-2 cells and induce increased Mx gene expression (generic assay detecting isoforms 1 and 3 [Mx1/3]). A trout pathogenic, genotype Ia isolate (J167), showing high replication in RTG-2 cells (by infective titre and N gene expression) induced lower Mx1/3 gene expression than observed in VHSV isolates known to be non-pathogenic to rainbow trout: 96-43/8, 96-43/10 (Ib); 1p49, 1p53 (II); and MI03 (IVb). Paired co-inoculation assays were analysed using equal number of plaque forming units per ml (PFU) of J167 (Ia genotype) with other less pathogenic VHSV genotypes. In these co-inoculations, the Mx1/3 gene expression was significantly lower than for the non-pathogenic isolate alone. Of the three rainbow trout Mx isoforms, J167 did not induce Mx1 up-regulation in RTG-2 or RTgill-W1 cells. Co-inoculating isolates resulted in greater inhibition of Mx in both rainbow trout cell lines studied. Up-regulation of sea bream Mx in SAF-1 cells induced by 96-43/8 was also lower in co-inoculation assays with J167. The RTG-P1 cell line, expressing luciferase under the control of the interferon-induced Mx rainbow trout gene promoter, showed low luciferase activity when inoculated with pathogenic strains: J167, DK-5131 (Ic), NO-A-163/68 (Id), TR-206239-1, TR-22207111 (Ie), 99-292 (IVa), and CA-NB00-01 (IVc). Co-inoculation assays showed a J167-dose dependent inhibition of the luciferase activity. The data suggest that virulent VHSV isolates may interfere in the interferon pathways, potentially determining higher pathogenicity.


      PubDate: 2016-03-21T19:27:23Z
       
  • Identification of amino acids in H9N2 influenza virus neuraminidase that
           are critical for the binding of two mouse monoclonal antibodies
    • Abstract: Publication date: Available online 16 March 2016
      Source:Veterinary Microbiology
      Author(s): Zhimin Wan, Jianqiang Ye, Jianjun Sang, Hongxia Shao, KunQian, Wenjie Jin, Aijian Qin, Hongquan Wan
      Neuraminidase (NA) is one of the major glycoproteins on the surface of influenza virus. It cleaves the linkage between haemagglutinin and cell surface receptors, and thus helps the release and spread of influenza virus. Despite the importance of H9N2 virus in influenza pandemic preparedness, the antigenic characteristics of its surface glycoproteins, especially NA, remains to be investigated. In the present study, we characterized two monoclonal antibodies (mAbs), 1D1 and 1G8, which are against the NA of an H9N2 virus A/Chicken/Jiangsu/X1/2004 (X1). We examined the inhibitory effect of these mAbs in two NA inhibition assays: enzyme-linked lectin assay (ELLA) and 2′-(4-methylumbelliferyl)-a-D-N-acetylneuraminic acid (Mu-NANA) assay. In ELLA, which uses a large molecule fetuin (molecular weight: 50 kd) as substrate, both antibodies effectively inhibit the NA activity of X1 virus. However, in Mu-NANA assay, which uses the small molecule Mu-NANA (molecular weight: 489 d) as substrate, antibody 1G8 inhibits the NA activity, while antibody 1D1 does not. Three amino acid mutations, at positions 198, 199 and 338, respectively, were detected in the NA of escape mutants of X1 virus selected with the two antibodies. Natural mutations at these three positions have occurred, indicative of immune pressure on H9N2 virus in the field. Our findings lay a basis for detailed investigation on the antigenic structure of H9N2 virus NA, which may be helpful for developing NA-based antibody reagents as well as vaccines.


      PubDate: 2016-03-17T19:06:58Z
       
  • Low prevalence of porcine circovirus type 2 infections in farrowing sows
           and corresponding pre-suckling piglets in southern German pig farms
    • Abstract: Publication date: Available online 16 March 2016
      Source:Veterinary Microbiology
      Author(s): M. Eddicks, M. Mueller, S. Willi, R. Fux, S. Reese, G. Sutter, J. Stadler, M. Ritzmann
      Porcine circovirus type 2 (PCV2) is the assumed causative agent of a number of different diseases summarized as porcine circovirus diseases (PCVD). The virus is shed via different se- and excretions of PCV2 infected pigs. Transmission of the virus occurs horizontally and vertically either by oronasal or diaplacental infection. Recent research emphasizes the importance of diaplacental PCV2 infection or the infection in early stages of the piglet’s life attributable to excretion of PCV2 by the dams within the suckling period. To estimate the prevalence of intrauterine PCV2 infections under field conditions in Bavaria the PCV2 status of farrowing sows (n=198) and corresponding pre-suckling piglets (n=590) of 20 piglet producing farms was examined. PCV2 viral load and anti-PCV2 antibodies in the serum of the sows and piglets were examined at time of farrowing or before colostrum intake, respectively. PCV2 excretion of the sows via saliva, feces and urine was examined additionally. PCV2 specific antibodies in the serum of the sows were detectable on 11 farms with a mean in herd seroprevalence of 35.5% in these farms. Only 0.65% of all samples collected from 198 sows were positive for PCV2 DNA (serum: 1%; feces: 0.5%; saliva: 0.5%; urine: 0.6%). PCV2 DNA was detectable in sample material from seronegative sows as well as from seropositive sows. In none of the pre-suckling serum samples of the piglets IgG antibodies against PCV2 or PCV2 DNA were present. No correlation between the antibody- and viremia status of the sows and the PCV2 excretion was detectable. In contrast to reports about a high prevalence of viremic pre-suckling piglets in the suckling period in North America, the results of the present study reveal that diaplacental infection with PCV2 is comparatively rare in Southern Germany and infection of piglets within the suckling period seems to be more likely.


      PubDate: 2016-03-17T19:06:58Z
       
  • Controlling equine influenza: traditional to next generation serological
           assays
    • Abstract: Publication date: Available online 10 March 2016
      Source:Veterinary Microbiology
      Author(s): Rebecca Kinsley, Simon D. Scott, Janet M. Daly
      Serological assays provide an indirect route for the recognition of infectious agents via the detection of antibodies against the infectious agent of interest within serum. Serological assays for equine influenza A virus can be applied for different purposes: diagnosing infections; subtyping isolates; surveillance of circulating strains; and to evaluate the efficacy of vaccines before they reach the market. Haemagglutination inhibition (HI) and single radial haemolysis (SRH) assays are most commonly used in the equine field. This review outlines how both these assays together with virus neutralization (VN) and ELISA are performed, interpreted and applied for the control of equine influenza, giving the limitations and advantages of each. The pseudotyped virus neutralization assay (PVNA) is also discussed as a promising prospect for the future of equine influenza virus serology.


      PubDate: 2016-03-13T18:46:19Z
       
  • Serologically silent, occult equine infectious anemia virus (EIAV)
           infections in horses.
    • Abstract: Publication date: Available online 11 March 2016
      Source:Veterinary Microbiology
      Author(s): Sonia Ricotti, Maria Inés Garcia, Carolina Veaute, Alejandra Bailat, Eduardo Lucca, R. Frank Cook, Sheila J. Cook, Adriana Soutullo
      Molecular and serological techniques for Equine Infectious Anemia Virus (EIAV) diagnosis were compared using samples from 59 clinically normal horses stabled on five farms in the Santa Fe Province of Argentina. Of these 26 (44.1%) were positive in official AGID tests and/or gp45/gp90-based ELISA. Surprisingly 18 of the 33 seronegative horses were positive in a PCR against viral sequences encoding gp45 (PCR-positive/AGID-negative) with all but one remaining EIAV-antibody negative throughout a two year observation period. The gp45 PCR results are supported by fact that 7/18 of these horses were positive in the Office International des Epizooties (OIE) recommended EIAV gag gene specific PCR plus 2 of this 7 also reacted in a PCR directed predominantly against the 5′ untranslated region of the viral genome. Furthermore sufficient quantities of serum were available from 8 of these horses to verify their seronegative status in sensitive Western Blot tests and demonstrate by ELISA the absence of EIAV-specific antibodies was not attributable to abnormalities in total IgG concentration. Studies involving 7 of the PCR-positive/AGID-negative horses to measure lymphocyte proliferation in the presence of PHA showed no significant differences between this group and control animals. In addition, lymphocytes from 2 of these 7 horses responded to peptides derived from gp90 and gp45. Together these results demonstrate that apparently clinically normal horses with no gross signs of immunodeficiency in terms of total IgG concentration or T helper-cell function can remain seronegative for at least 24 months while harboring EIAV specific nucleic acid sequences.


      PubDate: 2016-03-13T18:46:19Z
       
  • Downregulation of Protein Kinase PKR Activation by Porcine Reproductive
           and Respiratory Syndrome Virus at Its Early Stage Infection
    • Abstract: Publication date: Available online 7 March 2016
      Source:Veterinary Microbiology
      Author(s): Yueqiang Xiao, Zexu Ma, Rong Wang, Liping Yang, Yuchen Nan, Yan-Jin Zhang
      The interferon-induced double-strand RNA activated protein kinase (PKR) plays an important role in antiviral response. The objective of this study was to assess the effect of porcine reproductive and respiratory syndrome virus (PRRSV) on PKR activation. Here we report that PRRSV inhibited PKR activation during its early stage infection of primary pulmonary alveolar macrophages (PAMs). PRRSV infection led to lower level of phosphorylated PKR in comparison with mock-infected cells. The PKR inhibition was sustained until 10hours post infection in the presence of polyI:C, a synthetic analog of double-stranded RNA activating PKR. PKR-mediated phosphorylation of the eukaryotic translation initiation factor eIF2α was also lower in the PRRSV-infected PAMs during the early stage infection. Interestingly, inactivated PRRSV was capable to inhibit the PKR activation until 6hours post infection. This suggests that structural components of PRRSV virions were responsible for the inhibition, although PRRSV replication was needed for longer inhibition. These results indicate that the downregulation of PKR activation during early infection stage should be essential for PRRSV to avoid the antiviral response to initiate replication. This finding contributes to our understanding on PRRSV interaction with host innate immune response and reveal a target for control of PRRSV infection.


      PubDate: 2016-03-09T18:32:21Z
       
  • Prophylactic potential of resiquimod against very virulent infectious
           bursal disease virus (vvIBDV) challenge in chicken
    • Abstract: Publication date: Available online 9 March 2016
      Source:Veterinary Microbiology
      Author(s): Arunsaravanakumar Annamalai, Saravanan Ramakrishnan, Swati Sachan, B.S. Anand Kumar, Bal Krishan Sharma, Vimal Kumar, Munuswamy Palanivelu, Berin P. Varghese, Ajay Kumar, B.C. Saravanan, Narayanan Krishnaswamy
      The study evaluated the prophylactic potential of resiquimod (R-848), a synthetic TLR7 agonist, against very virulent infectious bursal disease virus (vvIBDV) infection in chicken. Specific pathogen free White Leghorn chicks of three week age were treated with R-848 (50μg/bird, intramuscular) or PBS (n=26/group). Twenty four hour later, half of the birds from each group were challenged with 105 ELD50 of vvIBDV and observed for 10 days. To understand the effect of R-848, immune response genes such as interferon (IFN)-β, IFN-γ, IL-1β, IL-4, iNOS and TLR7 were analyzed at 24 and 48h post-challenge in PBMCs ex vivo by real-time PCR (n=6/group). On day 4 post-challenge, representative birds (n=3/group) were sacrificed to study the bursal damage and IBDV antigen clearance. Immunosuppression was assessed by antibody response against live Newcastle disease virus (NDV) vaccine, which was administered on day 10 post-challenge. R-848 pre-treatment significantly up-regulated the transcripts of each immune response gene studied (P < 0.05). There was 50% mortality on vvIBDV challenge in control birds, while it was only 20% with R-848 group. R-848 pre-treatment reduced the bursal damage as indicated by lower bursal lesion score in histopathology, reduced IBDV antigen signal in immunohistochemistry and improved antigen clearance in agar gel immunodiffusion test. Further, it protected significantly against vvIBDV induced immunosuppression as indicated by HI antibody titre. It is concluded that pre-treatment of R-848 conferred partial protection from mortality and bursal damage while complete protection against immunosuppression in chicken when challenged with vvIBDV, which could be due to the up-regulation of immune response genes.


      PubDate: 2016-03-09T18:32:21Z
       
  • Adaptive amino acid substitutions enhance the virulence of a novel human
           H7N9 influenza virus in mice
    • Abstract: Publication date: Available online 3 March 2016
      Source:Veterinary Microbiology
      Author(s): Yongkun Zhao, Zhijun Yu, Linna Liu, Tiecheng Wang, Weiyang Sun, Chengyu Wang, Zhiping Xia, Yuwei Gao, Bo Zhou, Jun Qian, Xianzhu Xia
      To identify molecular features that confer enhanced H7N9 virulence in mammals, we independently generated three mouse-adapted variants of A/Shanghai/2/2013 (H7N9) by serial passage in mice. The mouse lethal doses (MLD50) of the mouse-adapted variants were reduced>1000 to 100000-fold when compared to the parental virus. Adapted variants displayed enhanced replication kinetics in vivo, and were capable of replicating in multiple organs. Analysis of adapted viral genomes revealed a total of 14 amino acid changes among the three variant viruses in the PA (T97I, K328R, P332T, and Q556R), HA (H3 numbering; A107T, R220I, L226Q, and R354K), NP (A284T and M352I), NA (M26I, N142S, and G389D), and M1 (M128R) proteins. Notably, many of these adaptive amino acid changes have been identified in naturally occurring H7 isolates. Our results identify amino acid substitutions that collectively enhance the ability of a human H7N9 virus to replicate and cause severe disease in mice.


      PubDate: 2016-03-04T18:16:05Z
       
 
 
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